diff --git a/layout/forms/crashtests/378369.html b/layout/forms/crashtests/378369.html
new file mode 100644
index 000000000000..90327735efdf
--- /dev/null
+++ b/layout/forms/crashtests/378369.html
@@ -0,0 +1,19 @@
+<html>
+<head>
+<title>Testcase bug - Crash [@ nsEventListenerManager::FixContextMenuEvent] when firing contextmenu event in display: none iframe</title>
+</head>
+<body>
+This page should not crash Mozilla
+<iframe style="display: none;"></iframe>
+
+<script>
+function docontextmenu(i){
+var doc = window.frames[0].document;
+  var ev = doc.createEvent ('MouseEvents'); 
+  ev.initMouseEvent('contextmenu', true,true, window, 3,5, 5, 400, 400, 0, 0, 0,0,0,null);
+  doc.dispatchEvent(ev);
+}
+setTimeout(docontextmenu,0);
+</script>
+</body>
+</html>
diff --git a/layout/forms/crashtests/crashtests.list b/layout/forms/crashtests/crashtests.list
index 8d2b4e5550f3..dd1a3425e6ae 100644
--- a/layout/forms/crashtests/crashtests.list
+++ b/layout/forms/crashtests/crashtests.list
@@ -20,6 +20,7 @@ load 367587-1.html
 load 370703-1.html
 load 370940-1.html
 load 373586-1.xhtml
+load 378369.html
 asserts(5-10) load 378413-1.xhtml # bug 424225, bug 402850?
 load 380116-1.xhtml
 load 382212-1.xhtml
